1. Field of the Invention
The invention relates in general to a method of image processing and associated apparatus, and more particularly, to a method for separating an image object from an image according to a three-dimensional (3D) depth and associated apparatus.
2. Description of the Related Art
With the ability to enhance quality, data amount, data content, and amusement of static and/or dynamic images, image processing and synthesis have become prevalent in modern society. For example, background removal is a common image processing performed on digital images. The image background removal process captures significant foregrounds of the image as independent image objects, so that the foregrounds can be separated from the remaining, less important background portions.
In the prior art, background removing is generally performed with chroma keying. During chroma keying, main substances forming the foregrounds are placed in front of a monochromatic (blue or green) background to be captured with the monochromatic background as an image. Subsequently, with post-image processing, the monochromatic background is removed from the image and the foregrounds are obtained as foreground image objects, which are then synthesized with a separately formed background image to form a new image. In another conventional background removing technique, the foreground image objects are separated from the background according to edges and/or color differences between the foreground objects and the background.
However, the above solutions associated with the prior art suffer from various application drawbacks. For example, when colors of certain parts of the foreground objects approximate or are identical to a color of the background, the parts are improperly removed during the background removal, and incomplete foreground objects are then formed. Furthermore, for a rather complicated foreground and/or a foreground with less apparent edges between the foreground and the background, difficulties may arise when applying the prior art techniques to correctly acquire the foreground image objects from the image.